A light-sensitive material package unit is known, with which one can take a photograph of a view through a finder simply by removing the outer package and pressing a shutter, and have the exposed film developed and printed simply by handing over the unit as it contains the film to a photofinishing laboratory. Such a package unit has been sold by Eastman Kodak under the name of "box camera". Its sale was, however, suspended because of inferior photographic quality and unhandiness.
In order to overcome such problems, the present inventors have previously made several inventions, as described, e.g., in Japanese Utility Model Application Nos. 75091/86 and 75794/86.
In the package units proposed by the present inventors, a photographic film is wound on a pair of reels shielded from light, with the area to be exposed to light being exposed. A package containing the film has such a structure that an image may be formed on the exposed area of the film through an optical lens system upon pressing a shutter plate fixed to a case. The light-sensitive material is protected from the outer atmosphere by the case and the outer package similarly to the conventional package units. Aiming at handiness and promptness for catching a shutter chance, this package unit employs a fixed focus system as an optical lens system, and, therefore, the exposure time is accordingly limited.
Additionally, since these light-sensitive material package units generally lack exposure latitude, one has to make a choice between those for outdoor use and those for indoor use. In addition, color images of high quality can hardly be obtained by such indoor photography.
Therefore, it has been desired to eliminate the above-described disadvantages by improving the light-sensitive material per se to be incorporated in the package unit. This is, the light-sensitive material to be used in the package unit is required firstly to have an improved exposure latitude, and secondarily to have improved image quality, such as sharpness, perspective, and texture even when exposed through a fixed focus system.
It is also possible to add a photochromic function hereinafter described to the exposure function of the unit. In such a case, also, the light-sensitive material to be used is required to fulfill the above requirements.